This invention relates to rifle mechanisms, and more particularly to a rifle mechanism capable of providing a high rate of fire.
Presently available automatic weapons designed and developed for military and individual use generally have firing rates in the range of 500 to 1,000 shorts per minute. There are, of course, weapons mechanisms which have normal rates of fire up to 2,500 shots per minute. As these mechanisms are pushed to higher cyclic rates, reliability and durability tend to fall off rapidly. When a round is fired in the prior art weapons, the moving elements must extract the empty case from the chamber, eject it and cock the hammer (if there is one) on the rearward stroke. The moving elements must also transfer energy to a storage device, usually a drive spring or buffer, and be brought to rest. On the forward stroke, a new round must be stripped from the magazine and chambered for firing.
For military rifle cartridges, the above-described sequence requires that the moving parts have average velocity of from ten to fifteen feet per second in order to provide cyclic rates of 1,500 to 2,000 shots per minute. Peak velocities may run several times higher than the average velocity, reaching forty to sixty feet per second in most weapons. At these high velocity rates, spring surging is a very serious concern and impact loads at these high velocities are very high. These high impact velocities produce stresses which may drastically shorten parts life.
There are, of course, high-rate-of-fire mechanisms known in the art. However, these weapons are generally multi-barreled weapons such as the Gatling gun which operate reliably at rates of fire of up to 6,000 shots per minute. These systems, because of the number of barrels and multiple bolt assemblies, are too heavy and bulky for use by the individual rifleman. High-rate-of-fire (2000 spm) rifle mechanisms that can provide a burst of three rounds or more have also been designed. Unfortunately, the current state-of-the-art requires that such weapons utilize a round counter mechanism that is connected to the trigger sear mechanism. The most successful weapon of this type (known to the inventors) utilizes a mechanism which is, for all practical purposes, as intricate as a clock mechanism. Such a mechanism is far too complicated expeditious field use and maintenance.
This invention solves the problem of obtaining a high rate of fire and a burst control mechanism with a minimum number of components.